The subject invention pertains generally to non-linear varying electrical signals and specifically to a technique for generating same.
Quite often, in performing control functions with electrical signals, it is desired or necessary to afford an output function which is not linearly related to the input signal. For example, where varactors are used to tune radio receivers, the capacitance does not normally vary linearly as a function of frequency (in order to optimize performance) thus necessitating a non-linear control signal. Although the non-linear control signal could be generated directly from the mechanism performing the control function (such as the frequency tuning knob in the case of a radio receiver) it may be more expeditious to first develop a linear signal therefrom and then to convert that signal to a non-linear signal for implementing the non-linear control function relationship.
Although there are a number of techniques for developing an output signal which is a non-linear function of an input signal, they normally exhibit various disadvantages. For example, one electromechanical technique which entails driving a non-linear potentiometer from a linear potentiometer requires precise components and introduces mechanical inertia delays which detract from the response time. Another more prominent technique employs the well known linear-piecemeal approximation approach utilizing diode wave shaping to generate straightline sections which are superposed together to simulate the non-linear curve relating the output to the input. The major disadvantage with this approach is of course the difficulty in achieving smooth transitions between adjacent segments as well as simulating the natural curvature with straightline sections so as to efficaciously reproduce the continuously smooth non-linear curve.
With the foregoing in mind, it is a primary object of the present invention to provide a new and improved technique for generating an output signal which is a non-linear function of an input signal.
It is a further object of the present invention to provide such a technique which effectuates the non-linear curve simulation more efficaciously than heretofore.
It is still a further object of the present invention to provide such a new and improved technique which affords great design flexibility, yet is easily implemented.
The foregoing objects as well as others and the means by which they are achieved may best be appreciated by referring to the Detailed Description of the Preferred Embodiment which follows hereinafter together with the attached drawings.